1. Field of the Invention
The present invention relates to a method of mounting an electrical component to a printed circuit board. More particularly, it relates to a method of mounting an electrical component on a printed circuit board having an opening near where the component is mounted to the board for allowing the output or the like of the component to be adjusted.
2. Description of the Prior Art
One form of electrical component mounted to a printed circuit board in this manner is a miniature variable capacitor of the type used in the tuning of AM radio receivers or the like. Such capacitors have their terminals and operating rods protruding in the same direction and after mounting the variable capacitor on a printed circuit board, the operating rod is operated from the rear side of the board through the opening therein. Thus, an appliance equipped to carry such a miniature variable capacitor has an enhanced efficiency for the mounting of the capacitor to the printed circuit board, and has reduced space requirements.
Prior art methods of mounting electrical components of this type are illustrated in FIGS. 1 and 2 of the accompanying drawings. An opening 3 for operating a rod 4 is provided in a printed circuit board 1 in advance. Connecting terminals 5 and grounding terminals 6 of a miniature variable capacitor 2 are inserted through respective apertures in the board 1. A conductive pattern on the rear side of the board 1 and the respective terminals 5 and 6 of the variable capacitor 2 are connected and fixed at one time by the use of immersion soldering (automatic soldering). Since, however, the operating rod 4 and a part of the variable capacitor 2 face towards the soldering bath through the opening 3, solder and solvent must be prevented from adhering to the operating rod 4 or entering the interior of the variable capacitor 2 through a bearing portion or the like to deteriorate the performance of the capacitor. To this end, the rod 4 is normally covered with a heat resistant cap 7 as illustrated in FIG. 1, or a heat resistant tape 8 is used to close the opening 3 as illustrated in FIG. 2.
The prior art methods are accordingly disadvantageous in that the step of depositing the heat resistant cap 7 or the heat resistant tape 8 before the soldering, and the step of detaching the cap 7 or the tape 8 after the soldering are required and the job is thereby complicated. A more serious disadvantage is that an extra part in the form of the cap 7 or the tape 8 is originally required.